Miniature Pig Heart Atlas Reveals a Unique Lipid-Burning Cardiomyocyte Subpopulation

The Wuzhishan miniature pig has long been considered one of the most promising large-animal models for cardiac research and xenotransplantation, prized for its physiological closeness to humans and its manageable size. Yet despite its growing importance in translational medicine, no comprehensive map of the cellular makeup of its heart existed—until now. A team of researchers from the Hainan Academy of Agricultural Sciences has constructed the first high-resolution single-cell and single-nucleus transcriptomic atlas of the Wuzhishan miniature pig heart, and in doing so has uncovered a surprise: a cardiomyocyte subpopulation with exceptionally active lipid metabolism that appears to exist only in this breed.

The study, published in BMC Genomics, spans five critical developmental stages of the heart, from the neonatal period through adulthood. By combining single-cell RNA sequencing, which captures individual cells, with single-nucleus RNA sequencing, which profiles the genetic activity of nuclei isolated from cells that are difficult to dissociate, the researchers were able to build an integrated picture of the postnatal cardiac landscape. This dual approach is particularly important for heart tissue, where mature cardiomyocytes are large, fragile, and notoriously resistant to standard single-cell preparation techniques.

With this atlas in hand, the team systematically characterized the full cellular panorama of the developing pig heart, documenting how different cell populations emerge, mature, and reorganize as the animal grows. Beyond simply cataloguing cell types, the researchers traced the dynamic changes in gene expression that accompany postnatal cardiac maturation, a period during which the heart transitions from a proliferative, immature state to the hypertrophic, contractile state that defines the adult organ. They also mapped the remodeling of intercellular communication networks—the signaling conversations between cardiomyocytes, fibroblasts, endothelial cells, immune cells, and other residents of the heart—that orchestrate this developmental progression.

The most striking finding emerged from cross-species comparative analysis. When the researchers compared the pig heart atlas with single-cell data from other species, they identified a ventricular cardiomyocyte subpopulation, which they named VCM-LM-SR, characterized by highly active lipid metabolism. This subpopulation is specific to the Wuzhishan miniature pig; it does not appear in the other species examined. The discovery suggests that this breed has evolved, or been selectively bred toward, a distinct metabolic program in its heart muscle cells, one that relies heavily on fatty acid processing as an energy source.

What makes the VCM-LM-SR subpopulation particularly intriguing is its position within the adult cardiac cellular interactome. The researchers found that these lipid-metabolic cardiomyocytes occupy a hub position, meaning they serve as central nodes in the communication network connecting different cell types in the adult heart. Cells that act as hubs typically exert outsized influence over tissue function, coordinating signals and resources across the cellular community. The fact that a metabolically specialized cardiomyocyte subset holds this role hints at a previously unappreciated layer of metabolic regulation in cardiac homeostasis.

The cross-species comparisons also revealed something unexpected about the transcriptional baseline of the Wuzhishan miniature pig heart. The activity of multiple human cardiac disease-related pathways was found to be significantly lower in the pig’s cardiomyocytes compared with the other species examined. In other words, the genetic programs that, when dysregulated, drive heart failure, hypertrophy, and other cardiovascular conditions in humans appear to be running at a quieter baseline level in this donor animal. This finding has direct implications for how researchers interpret data from pig models of cardiac disease, because a lower baseline could mask or alter disease phenotypes in experimental settings.

For the xenotransplantation field, these results carry particular weight. Pig-to-human heart transplantation has moved from theory to clinical reality in recent years, with genetically engineered pig hearts successfully transplanted into human recipients. Understanding the cellular and molecular differences between pig and human hearts is essential for predicting how xenografts will behave after transplantation. The identification of a species-specific lipid-metabolic cardiomyocyte population, and the demonstration that disease-related pathway activity differs between pigs and other species, provides transplant researchers with new molecular features to consider when selecting and engineering donor animals.

The atlas also serves as a foundational resource for studying human cardiac metabolism using large-animal models. Rodent models, while genetically tractable, differ substantially from humans in cardiac physiology, metabolism, and disease susceptibility. Large animals such as pigs bridge this gap far more effectively, and a detailed reference map of the pig heart at single-cell resolution gives researchers a benchmark against which they can measure how cardiac cell states shift in response to disease, diet, surgical intervention, or genetic modification. The developmental dimension of the atlas adds further value, allowing investigators to pinpoint when specific cell populations or communication networks become established during maturation.

Technically, the study showcases the power of integrating single-cell and single-nucleus sequencing data. The researchers employed computational tools including Uniform Manifold Approximation and Projection for visualizing cell populations, differential expression analysis to identify marker genes, transcription factor regulon analysis to infer gene regulatory networks, and Gene Set Variation Analysis to assess pathway activity across cell types and developmental stages. This combination of methods allowed them to move beyond simple cell-type identification toward a functional understanding of how the heart’s cellular ecosystem changes over time and how it differs between species.

The work was funded by the National Key R&D Program Project and the Academician Workstation of the Hainan Academy of Agricultural Sciences, and all animal procedures were approved by the institute’s Animal Care and Use Committee. As genetically engineered pigs edge closer to routine clinical use as organ donors, and as metabolic heart disease continues to rise worldwide, resources like this atlas will become increasingly indispensable. By revealing that even within a single breed, the heart can harbor specialized metabolic cell states unique to that species, the study opens a new window onto the diversity of cardiac biology—and reminds researchers that the choice of model organism matters more, at the single-cell level, than ever before.

Subject of Research: Construction of a single-cell transcriptomic atlas of the Wuzhishan miniature pig heart across postnatal development and cross-species identification of a species-specific lipid-metabolic cardiomyocyte subpopulation.

Article Title: Single-cell atlas of the Wuzhishan miniature pig heart identifies a species-specific lipid-metabolic cardiomyocyte subpopulation

Article References: Xin, W., Li, C., Wang, Z., Han, J., Duan, D., Yuan, J., Qiao, C., Tan, S., Chao, Z., Wang, M., Zhou, S., & Li, X. (2026). Single-cell atlas of the Wuzhishan miniature pig heart identifies a species-specific lipid-metabolic cardiomyocyte subpopulation. BMC Genomics. https://doi.org/10.1186/s12864-026-13335-0

Image Credits: AI Generated

DOI: 10.1186/s12864-026-13335-0

Keywords: Wuzhishan miniature pig, single-cell atlas, cardiomyocytes, lipid metabolism, heart development, xenotransplantation, single-nucleus RNA sequencing, cross-species comparison, cardiac metabolism, BMC Genomics, translational model, cell communication